Valuation and Qualifying Accounts Valuation and Qualifying Accounts (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009		Dec. 31, 2008
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance	$ 450		$ 460		$ 1,670		$ 1,669
Amounts Charged (Credited) to Costs and Expenses	159		54		7
Deductions	$ (169)	[1]	$ (1,264)	[1]	$ (6)	[1]

[1] Accounts written off, net of recoveries.